In recent years, radio communication apparatuses capable of communicating with GPS (Global Positioning System) or base stations (access points) of wireless LAN (Local Area Network) have been widely used. Such a radio communication apparatus can estimate the position of the local apparatus by using GPS positioning or wireless LAN. Position estimation technology using such a radio communication apparatus is an important common basic technology in wide-ranging fields such as navigation, security, and entertainment. However, according to the position estimation technology based on GPS positioning, it takes a long time to supplement synchronization during activation and it is difficult to use such a radio communication apparatus indoors or underground where a radio signal from a satellite is not receivable.
The position estimation technology using wireless LAN, on the other hand, is a technology to estimate the position of a radio communication apparatus based on signal strength of radio signals received by the radio communication apparatus from base stations and position information of the base stations registered in advance. Since base stations of wireless LAN are set up also indoors or underground, indoor or underground position estimation is enabled according to the position estimation technology using wireless LAN, which is difficult to achieve according to the position estimation technology based on GPS positioning. That is, the above position estimation method can be considered to be a position estimation technology excellent in convenience and ease if base station information indicating positions of base stations of wireless LAN set up around a radio communication apparatus is registered in a position estimation apparatus.
Thus, technology to construct a database of base station information of wireless LAN has nowadays been proposed. In Patent Document 1, for example, a method by which base station identification information received by a radio communication apparatus having a current position acquisition function and the current position of the radio communication apparatus acquired by the current position acquisition function are associated and registered is described. In Patent Document 2, a method by which base station identification information contained in a radio signal received from a base station of wireless LAN and position information acquired by using a GPS receiving function are associated for registration in a vehicle equipped with the GPS receiving function and wireless LAN communication function is described.